On the first Friday night after a woman gets married, when she lights the Shabbat candles for the first time, should she recite the Beracha of "Shehehiyanu" in celebration of her first time fulfilling this Misva?
A similar question arises when a boy wears Tefillin for the first time, upon reaching the age of Bar Misva. Does he recite "Shehehiyanu" on the occasion of performing this Misva for the first time?
The Tosefta in Masechet Berachot (6:15) indicates that one does, indeed, recite "Shehehiyanu" the first time he performs the Misva of Tefillin, and this is the position taken by the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204), in Hilchot Berachot (11:9). However, Tosafot (commentaries to the Talmud by Medieval French and German scholars) in Masechet Menahot write (citing Rav Sherira Gaon) that Halacha does not follow this ruling of the Tosefta. The Beracha of "Shehehiyanu," Tosafot explain, is recited when one performs a Misva which applies on rare occasions. The Misva of Tefillin, of course, is performed each day, except for Shabbat and holidays. Since we perform this Misva on a regular basis, it does not warrant the recitation of "Shehehiyanu," even when one observes this Misva for the first time.
Tosafot address in this context the Halacha presented in the Gemara (there in Masechet Menahot) concerning a Kohen who offers a Minha (meal offering) in the Bet Hamikdash for the first time. The Gemara establishes that a Kohen does, indeed, recite the Beracha of "Shehehiyanu" the first time he offers a Minha. The Misva of the Minha offering clearly was a regular event; it was brought each and every day in the Bet Hamikdash. Yet, the Gemara explicitly requires reciting "Shehehiyanu" the first time one performs this Misva, seemingly indicating that one must recite this Beracha whenever he performs a Misva for the first time, even if it is a Misva which he will then perform regularly. As Tosafot note, however, a given Kohen brought a Minha offering only twice a year, at most. The Kohanim were divided into twenty-four groups called Mishmarot, which served in the Bet Hamikdash on a rotating basis, according to a weekly rotation. Thus, each Mishmar served for only two weeks a year, and each Kohen in each group would be assigned one day during each week. Therefore, for any individual Kohen, offering a Minha was indeed a rare occurrence, which warranted the recitation of "Shehehiyanu." When one wears Tefillin for the first time, however, he would not recite this Beracha, since Tefillin is worn regularly, almost every day.
It should be noted that although it is customary to recite "Shehehiyanu" when wearing a Tallit for the first time, this is done on account of the fact that one wears a new garment. The Beracha is recited not over the performance of the Misva, but rather over the experience of wearing a new garment for the first time. Indeed, it is customary for a Hatan (groom) to recite "Shehehiyanu" when he wears his new Tallit under the Hupa, even if the wedding takes place at nighttime, when the Misva of Sisit does not apply. This proves that the Beracha is recited on account of the new garment, and not because of the Misva.
In light of the debate among the authorities in this regard, we follow the rule of "Safek Berachot Le’hakel" (a Beracha should not be recited if there is some uncertainty as to whether it is warranted), and thus a Bar Misva boy does not recite "Shehehiyanu" when he wears Tefillin for the first time. This applies as well to a bride lighting Shabbat candles for the first time; she does not recite "Shehehiyanu" on this occasion. If she wishes to recite the Beracha, she should wear a new garment and recite "Shehehiyanu" over the garment just before lighting Shabbat candles, having in mind that the Beracha should apply also to the Misva of Shabbat candles. Similarly, if a Bar Misva boy so desires, he can wear a new suit on the morning he wears Tefillin for the first time, and have in mind that the Beracha should apply as well to the Misva of Tefillin.
Summary: A woman does not recite "Shehehiyanu" when she lights Shabbat candles for the first time after she gets married. If she wants, she may wear a new garment and recite "Shehehiyanu" over the garment before candle lighting, having in mind for the Beracha to apply as well to the Misva of Shabbat candles. The same applies to a Bar Misva boy who puts on Tefillin for the first time.
